Seasonal variations of brightness temperature at 85 GHz over India Original Research Article

The data recorded by the Special Sensor Microwave Imager (SSM/I) at 85 GHz over India during 1987–1988 have been analysed. The brightness temperature shows distinct pattern, which is attributed to the presence of varying rock types, soil, snow and water. The seasonal variations of brightness temperature especially in high altitude region is attributed to the varying degree of snow thickness and snow melting. The brightness temperature over three geological divisions of Indian landmass are found to vary and show three characteristic geological divisions of India. The monthly average brightness temperature over Arabian Sea, Indian Peninsular region, Indo-Gangetic basin and Himalayan region depict significant variations. These variations are attributed mainly to the changes in surface temperature and due to the atmospheric perturbations.